Abstract: Using the global ocean-atmosphere-land coupled model (GOALS-AVIM) developed at the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences, the Indian Ocean sea surface temperature (SST) abnormality and its relations with the net primary production (NPP) at the land surface in South Asia are analyzed. The model is integrated for 50 years, and the integration results for the later 40 years are used in this work. Results show that there are four dominant steady patterns of annual mean Indian Ocean sea surface temperature anomaly (SSTA) in the Empirical Orthogonal Function (EOF). The first eigenvector exhibits a trend of simultaneous changes in the whole area, which demonstrates that the Indian Ocean SST in the four seasons possesses a consistent increase or decrease. Meanwhile, the trend is consistent with the NPP change at the land surface in South Asia. A correlation analysis shows that the consistent warming or cooling in the equatorial Indian Ocean has a positive lag correlation with the Niño3 index of the equatorial Pacific Ocean, and the lag time is eight months. The second eigenvector shows that the tropical Indian Ocean SST displays a characteristic of the Indian Ocean Dipole (IOD) oscillation with two steady shapes of west-high－east-low and east-high－west-low. The dipole has an obvious seasonal variation, and its seasonal phase locking is also obvious. The abnormal trend of consistent changes in the Indian Ocean SSTA is highly related to the changes in seasonal and annual mean NPP at the land surface in South Asia with lag or contemporary correlation. The positive and negative phases of the first EOF mode of the summer Indian Ocean SST that has a high correlation with annual mean NPP in South Asia correspond to distinct anomalies of 850-hPa wind field, 500-hPa geopotential height field and precipitation field in South Asia. The analysis indicates that the increase or decrease of summer monsoon in the Indian Ocean and South Asia causes the precipitation abnormity in South Asia, which results in the increase or decrease of NPP abnormity in this region.